A patient on lisinopril reports a cough. Which side effect is most commonly associated with ACE inhibitors like lisinopril?

• A. Hyperkalemia
• B. Dizziness
• C. Cough
• D. Angioedema

Answer: (C)

ACE inhibitors commonly cause a dry, persistent cough due to buildup of bradykinin when the enzyme that degrades it is blocked. This increased bradykinin in the airways can irritate receptors and promote coughing, which is why a cough is the most frequent side effect seen with lisinopril and other ACE inhibitors. Other listed effects like dizziness and hyperkalemia can occur because ACE inhibitors lower blood pressure and reduce aldosterone, leading to potassium retention, but these are less characteristically tied to the cough. Angioedema is a known but rarer and more serious reaction linked to bradykinin, not the typical cough. When cough becomes bothersome, clinicians may switch to a non-ACE option such as an ARB.